Hip Dysplasia in Pediatric Paralysis

Hip dysplasia occurs when the ball and socket joint of the hip separate. This can be ever so slightly or a major issue, but, in either case, it requires medical attention. When the joint is displaced, the bones can rub together, leading to injury to the bones, ligaments and impairing function. It can be very painful.

Most often, hip dysplasia is seen in children at birth or in early childhood. It can occur in individuals of any age with paralysis. It is an issue of the ball and socket hip joint in that the socket part of the joint is not fully formed at birth or due to muscle weakness in later ages, especially with paralysis.

Developmental dysplasia of the hip (DDH) can occur in any child at birth or develops in childhood. The American Academy of Family Physicians estimates the occurrence of hip subluxation to be 10 in 1,000 children and 1 in 1,000 for a dislocated hip. Some interesting facts about hip dysplasia are that it occurs more often in girls, with breech birth position, in the firstborn, and in those with a family history. It occurs least in those living in Africa, most in Polish Americans and Native Americans. The reason is related to differences in swaddling habits when the swaddle pulls on the hip joint. It can occur in either hip but more often occurs in just one hip and on the left side due to pressure of the uterus on the hip before birth (Loder, 2011).

Hip dysplasia can present in different forms. A dislocated hip occurs when the ball and socket bones are not in place. A dislocated hip occurs when the ball can be easily moved in and out of the socket. A subluxated hip occurs when the ball and socket are not properly seated together. A dysplastic hip occurs when the hip socket is not developed to hold the ball.

Paralysis can affect hip placement due to lax, weakened, or muscles with tone (spasticity). You may notice hip dysplasia if your child has a difference in leg lengths, a change in range of motion (decreased or increased), if the foot turns outward, or a limp or change in gait if walking. Hip dysplasia can be an issue if your child has sensation, pain, guarding of the displacement area, or changes in physical abilities. If the sensation is reduced, you may notice other changes in your child, such as irritability, increased tone (spasticity), or episodes of autonomic dysreflexia (AD). An AD wallet card is available here.

Tone or spasticity can be the result of hip dysplasia or can actually lead to hip dysplasia or dislocation. Hip dysplasia can lead to a muscle imbalance which may lead to increased tone. With tone (spasticity), one set of muscles with tone excessively pulls on the bone while the counterbalance set of muscles maintains the same or less pressure on the other side of the bone.

To diagnose hip dysplasia, your child’s healthcare professional will need to perform a physical examination of the hip. They will also do an x-ray or ultrasound. The ultrasound may need to be completed while moving the hip.

In infants, while the hip is still developing, a Pavlik splint is used to hold the hip in place. This is a soft splint that holds the ball of the top of the thigh bone into the socket of the hip. You can easily change the baby’s diaper with the Pavlik splint in place. It is worn full-time for several months and then part-time while your child’s body adjusts to being without it as the hip continues to develop.

Treatment of hip dysplasia in older children and teens or for those infants that do not have success with the Pavlik splint varies as their condition requires.

Reduction is the word used for the treatment of hip dysplasia or displacement. Closed reduction is a procedure performed using a general anesthetic, but no surgery. The hip is manipulated into the hip joint using fluoroscopy for guidance. A spica cast is used to hold the hip joint in place. A spica cast fits around the waist and hips with the cast extending down the leg of the hip with corrected dysplasia. The cast is open so a diaper can be used. Because of positioning issues of the cast, an adult wheelchair is often temporarily used to accommodate the child.

Open reduction is a surgical procedure to realign the ball of the leg bone into the socket of the pelvis. It is usually not performed until the child is at least 10 months old. There may need to be some bone removed if it is blocking placement or surgical adjustments to the bones for alignment. This is called a hip osteotomy. It is usually needed for the child over three or four years. The spica cast is then placed for about six to eight weeks, followed by a brace.

Hip dysplasia and dislocation should be taken seriously as lifelong complications in seating, mobility, and the development of osteoarthritis can occur. There are complications, especially with surgery, such as avascular necrosis, where blood to the bones is affected. Your surgeon will take caution to avoid this possibility. Be sure to ask about complications so you can make a well-formed decision about the risks and benefits of the surgery. However, early intervention with exercise, proper positioning both day and night, and careful handling of the body can help reduce the risk of hip dysplasia from paralysis.

Loder RT, Skopelja EN. The epidemiology and demographics of hip dysplasia. ISRN Orthop. 2011 Oct 10;2011:238607. doi: 10.5402/2011/238607. PMID: 24977057; PMCID: PMC4063216. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4063216/pdf/ISRN.ORTHOPEDICS2011-238607.pdf